Air-brake



(No Modem Jl Bl KNUDSEN. zsneets-sheet 1.

AIR BRAKE. No. 468,387. Patented Peb. 9, 1892.

(No Model.)

2 Sheets-Sheet 42. J. B. KNUDSEN.

AIR BRAKE.

UNITED STATESPATENT OFFICE.

JACOB Il. KNUDSEN, OF FERNIVOOD, ILLINOIS.

AIR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 468,387, dated February 9, 1892.

Application iiled December 30, 1890. Serial No. 376,213. (No model.)

To all whom it :n2/Cty con/cern:

Be it known that I, JACOB I3. KNUDSEN, a citizen of the United States, residing at Fernwood, inthe countyof Cook and State of Illinois, have invented certain new and useful Improvements in Air-Brakes, of which I do declare the following to be a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

Mypresent invention has relation more particularly to that class of air-brakes in which the compression of the air is effected by the operation of a pump driven from the axle of the car-wheels; and my improvements are directed more particularly to the construction of mechanism for operatingthe piston of the air pump or compresser.

These improvements have for their object, primarily, to insure the operation of the pump in order to maintain a proper supply of air within the storage-chamber or reservoir of the air -brake system and to provide for throwing the air-pump out of action when a plenum pressure within the storage-chamber or reservoir is reached.

Figure lis a view in vertical section through a portion of the car-floor and a portion of t-he truck-frame and car-axle, showing my improvements in position for operating the airpump, the cylinder ot the pump being also shown in vertical section. Fig. 2 is a detail view, partly in side elevation and partly in vertical section, of a portion of the air-pump,

its piston, and the actuating-arm for the pis` ton. Fig. 2 is a detail view, in vertical section, through the cylinder at the top of the throwoft bar. Fig. 3 isa view in vertical section of the driving-frame upon the car-axle. Fig. 4. is a perspective View of such frame, showing the drivin g-arm and supportingrod connected thereto. Fig. 5 is a view in vertical section on line 5 5 of Fig. l. Fig. G is a detail per spective view of the tilting bar whereby the drivingframeis carried. Fig. 7 is a View in transverse section online 7 7 of Fig. 5.

A designates the floor of the car, beneath which extends the truck-frame B, this frame being shown as connected to the transom C and to the car-door A by means of a suitable king-bolt I). The truck-frame is of wellknownconstruction and will be supported upon the axles of the carin the usual manner; but as this truck-frame forms no part of my present invention I have not deemed itnecessary to illustrate the saine in detail.

The cylinder E of the air-pump is sustained by a suitable bracket 2, that depends from the truck-frame B, and from this air-pump cylinder leads a discharge-pipac (provided with a suitable check-valve e) to a compressed-air reservoir located at any convenient point. lVithin the cylinder E works the piston E', the rod or stem E2 ot' which is provided with a cross-pin e2, adapted to be engaged by the connecting-arm F when the pump is to be operated. The connecting-arm F is united to the periphery of the drivingframe Gr, this frame being preferably formed of the rim or periphery g and the sides g', bolted thereto. The periphery g and the sides g may be formed in sections to permit them to be conveniently placed upon the caraxle.

To that part of the periphery g opposite the point at which the connecting-arm F is attached is united a guide-rod 5, that is mounted in the expanded end h of the throw-oft bar H. This throw-off bar II is provided, also, with the depending end 7b', adapted to engage with the connecting-arm F, a convenient method of effecting this engagement being to provide the sides of the arm F with the grooves f, into which the inwardly-bent en ds 7a2 of the throw-off bar will enter. The throw-oit bar II is sustained by means of the rod I, the yokeshaped ends'zof which are pivotally connected to the throw-off bar II by means of the pin fi. This rod I passes through a top plate K, that is supported by the truck-frame B, and upon eachA side of this top plate and encircling the rod I are placed the coiled springs 2 and t, which serve to sustain the throw-oit bar II in such manner that an elastic action thereof can be had to compensate for the movements of the truck-frame with respect to the caraxle. The slot 7b3 ofthe bar II, through which the pivot-pin t' passes, is made of asize somewhat larger than the bolt, so as to permit a longitudinal movement of this bar, as will be presently stated.

The side plates g of the shifting frame G are provided with the long openings g2 to permit this frame to move back and forth upon the car-axle X, and upon this axle and within the shifting frame G is fixed the driving-arm M, the outer portion of which is provided with a friction-roller m, that bears against the inner face of the periphery g of the shifting frame G. rThis driving-frame M is preferably formed in sections conveniently bolted together, as at m, as such construction permits the driving-arm to be readily placed in position on the axle.

The connecting-arm F is preferably formed,

with a channel f', adapted to partiallyinclose the piston-rod E2 of the air-pump, as the arm is thereby held in better working relation to the piston. The under side of the arm F is also furnished with notches f2, adapted to receive the pin e when this arm is to be thrown into engagement with the piston-rod E2 of the air-pumpl in order to supply compressed air to the compressed-air chamber or reservoir. By preference the arm F, when in the position shown in Fig. l, rests upon a spring-seated plate WV, carried at the lower portion of the suspension strap or frame O, that is bolted to and depends froln the top plate K of the truck-framenB, this springextensions w to retain it in position between the arms of the suspension strap or frame O.

From the foregoing construction it will be seen that if the parts are in the'position illustrated in Fig. 1 of the drawings and the car is put in motion the rotation of the axle X will cause aV corresponding revolution of the driving-arm M, and as this arm is revolved its friction-roll m will bear against the eccentrically-shaped peripheryg of the shifting frame G and will caus'e'a reciprocatingmovement of the arm F, attached to this frame. As the arm F is at such time engaged with the pin e2 of the piston-rod E2, it is manifest that a reciprocating movement of the piston-rod E2 and piston E will be effected, thereby causing the compression of air within the pump-cylinder E, from which cylinder the air will be conducted by the delivery-pipe e to a suitable chamber or reservoir, from whence it will be distributed to the car-brakes, as may be needed.V This operation of the pump will continue so long as the car is in motion and so long as the shifting-arm F is in engagement with the pin e2 of the piston-rod E2. When, however, a plenum pressure within the storage-chamber of the air-brake system is attained,it is desirable that the air-pum p should be thrown out of operation, and it is to effect this throwing of the air-pump out of operation that I have mounted the shifting frame G and its arm F in such manner that a ready disengagement of the arm F from the pistonrod can be secured. This disengagement of the arm F from the piston-rod E2 is secured by rockin g the throw-off bar H about the pivot-pin i', and while this4 rocking movement of the throw-off bar might be produced by a-treadle or lever connected to the throwoif bar still I prefer to provide means whereby an automatic movement of the throwoff bar and a consequent automatic disengagement of the connecting-arm F from the piston-rod E2 shall occur when a plenum pressure within the storage-chamber of the brake system has been reached. To accomplish this I connect to the rear end of the throw-off bar H a piston-rod P, thatmoves within a cylinder p, that is carried by the top plate K of the truck-frame B. The stem of this pistou rod P is pivotally connected to its head p and to the 'throw-off bar H, and upon this stem and within the cylinder p is carried a resistance-spring R, that bears against the head of the piston and the end of the cylinder with a predetermined force. Vith'the end of the cylinder p opposite that through which the piston P passes connects a pipe S, that also connects with the storage chamber or reservoir of the air-brake system,so that when a plenum pressure within such chamber or reservoir is reached the force of the resistance-spring R will be overcome, thereby permitting'the head p of the piston P to be depressed and causing this piston P, by reason of its connection with the throw-off bar H, to rock this bar about the pivot-pin i. As the arms of the throw-off bar H are attached to the connecting-bar F and the rod 5, it is manifest that as this throw-off bar is thus rocked the shifting frame G, the connecting-arm F, and the rod 5 will be correspondiugly moved and the con necting-arm F will be lifted to such extent as to disengagc this arm from the cross-pin e2 of the pistourod E2. Hence it will be seen that when such movement of the throw-off bar II occurs by reason of the plenum pressure within the storage chamber or reservoir of the air-brake system the air-pump will be thrown out of action and will remain out of action until the pressure of air within the storage chamber or reservoir is so far diminished as to permit the spring R to again lift the piston-rod P and shift the throw-off bar H in such manner as to again cause the connecting-arm F to engage with the cross-pin e2 of the piston-rod E2, as it is desirable that the piston-rod E2 shall remain as as possible within the cylinder E of the air-pump during the time that such pump is out of action. In order to protect the piston from accumulating dirt and dust, I provide that the end of the piston-rod E2 shall be struck by the shoulder or extension 10 at the base of the conn eating-arm F, so that after the disen gagement of the connecting-arm F and the pistonrod occurs the further movement of the shifting frame G will force the piston-rod E2 inward, where it will remain until a re-eugagement of the piston-rod and connectingarm occurs. My purpose in providing the IOO IOSY.

IIO

h 'of the throw-oit bar lI will be constantly maintained at uniform distances f rom the caraxle X, and consequently lthe striking of the shifting trame against the ends of these arms Will be avoided.

rlhe precise details of construction above set out may be varied Without departing from the spirit ot my invention, and to such details, therefore, I do not Wish the invention to be understood as restricted.

My improved mechanism above described, while applicable for use in other situations, is more particularly designed for air-brake systems of street-railway cars.

One advantage in forming the shifting frame G with the side plates and periphery, as shown, isV that the driving-arm is thereby very much better protected from the accumulation of dirt and dust than Would be possible if no side plates Were employed. The feature of forming the side plates and periphery of this shifting frame in sections and of forming the driving-arm in sections is also important, since it aitords a ready means whereby the parts may be attached to the axles ot the cars.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. In air-brake mechanism, the combination, with the air-pump, of' a connecting-arm adapted to engage the piston-rod of said pump, an eccentrically-shaped shifting frame for operating said connecting-arm, a guiderod attached to said shifting frame at a point opposite said connecting-arm,a pivoted throwott bar connected to said guide-rod and said connecting-arm, a driving-arm located Within said shifting frame and having a friction-roll adapted to bear against the periphery of said shifting frame, and suitable means for operating said throw-off bar, substantially as described.

2. In air-brake mechanism, the combination, with the air-pump, ot the connectingarln adapted to engage the piston-rod of said pump, a shiftin g frame for operating said connecting-arm, a pivoted throw-off bar for throwing said connecting-arm out of engagement with said piston-rod, a guide-rod attached to said shifting frame at a point opposite said connecting-arm, a pivoted throw-off bar for throwing said connecting-arm out of engagement with said piston-rod, a guide-rod attached to said shifting frame at a point opposite said connecting-arm, said throw-oft bar being attached to said guide-rod and said connecting-arm, a driving-arm Within said shift-` ing frame, a piston-rod connected to said throw-oit bar, a spring-seated piston for operating said piston-rod, a cylinder for said piston, and a suitable pipe for admitting air to said piston, substantially as described.

In air-brake mechanism, the combination, with the air-pump, of a connecting-arm adapted to engage the piston-rod of said pump, an eccentrically-shaped shifting frame for operating said connecting-arm, a guide-rod attached to said shifting frame, a throw-oit bar connected to said guide-rod and said connecting-arm and provided With a slot, a pivot-pin for said throw oft bar, passing through the slot thereof, and suitable means for rocking said throw-off bar about its pivotpin, substantially as described.

4. In air-brake mechanism, the combination, With the air-pump, of a connecting-arm adapted to engage the piston-redet said pump, a shifting frame for operatingr said connecting-arm, a throw-off bar for throwing said connecting-arm out of engagement with said piston-rod, a driving-arm for operating said shif ting frame, and suitable means for operating said throw-ott bar, said shifting-frame bar being furnished With a shoulderadapted to force the piston-rod into the cylinder after the disengagement ot the connecting-arm and piston-rod is effected, substantially as described.

5. In air-brake mechanism, the combination, With the air-pu in p, of a connecting-arm adapted to engage the piston-rodof said pump, a shifting frame for operating said connectin g-arm, athroW-olt bar for th rowing said connecting-arm out of engagement with said piston-rod, a pivot-rod and pivot-pin for sustaining said throW-oi bar, a top-plate for sustaining` said throw-oit bar, suitable springs for giving to said throw-off bar an elastic support, and suitable means for operating said throw-off bar, substantially as described.

(l. In air-brake mechanism, the combination, with the air-pump comprising a cylinderE and piston-rod E2, provided With a pin e?, of a connecting-rod F, adapted to engage said piston-rod, a shifting frame G, consisting of side plates g and periphery g, a driving-arm M Within said shifting frame and provided with a friction-roller ni at its end, a pivoted throw-off bar II, and suitable means for operating said throw-olt bar, substantially as de scribed.

7. In air-brake mechanism, the combination, with the air-pum p and its piston-rod E2, of a connecting-arm F, adapted to engage said piston-rod and provided with longitudinal slots f, a shifting frame G, to which said connecting-arm is attached, a guide-rod 5, also connected to said shifting frame, athro\ fott bar H, one arm of which is connected to said guide-rod 5 and the opposite arm of which has yoke-shaped portions adapted to IOO IIO

enter the slots f of the connecting-arm, a Y

pivot-pin for sustaining said throw-ott bar, and suitable means for operating said throwoit bar, substantially as described. 

